A coated article includes a single layer or multilayer coating supported by a substrate. Glass substrates oftentimes will be used in connection with coated articles, and oftentimes coatings will be thin film coatings formed by magnetron sputtering or the like.
Coated articles such as these may be used for a variety of applications including, for example, in low-emissivity (low-E) windows, reflective products (e.g., commercial or residential mirrors, solar reflectors, etc.), electronic applications (e.g., for radar, HF, or other dampening or transmitting applications; in flat panel displays, etc.), and/or the like. Antireflective (AR) coatings, bird protection coatings, UV light blocking coatings, and/or the like may be used with, integrated into, or used separately compared to these products.
To meet these and/or other needs, the coated articles may be used “on their own” (e.g., in monolithic products), laminated products (e.g., where two sheets of glass are bonded together using a polymer-based or other interlayer such as, for example, PVB, EVA, PET, PU, etc.), built into insulating glass units (IG units or IGUs) or vacuum insulating glass (VIG) units, used in structural glazings, and/or the like.
Oftentimes, it will be necessary or desirable to remove at least a portion of a coating. For example, it oftentimes is desirable to “edge delete” certain coatings. Edge deletion generally involves removing a portion of the coating around peripheral edges of the underlying substrate. Edge deletion can be helpful, for example, in reducing the likelihood of a coating deteriorating, as corrosion and damaging water ingress usually begin at unsealed peripheral edges, etc. In these and/or other applications, removal of a coating may be helpful in providing a more structurally secure surface for a material to bond to, e.g., in that a guide rail, handle, or other piece of hardware may form a more robust connection with bare glass as compared to an upper surface of a coating, etc. Similarly, in these and/or other applications, removal of a coating may be helpful in providing electrical isolation, etc.
Edge deletion tables are known. See, for example, U.S. Pat. Nos. 4,716,686; 5,713,986; 5,934,982; 6,971,948; 6,988,938; 7,125,462; 7,140,953; and 8,449,348, each of which is hereby incorporated herein in its entirety. In general, in such tables, a series of casters provided to the table allow for smooth movement of glass across the surface of the table. Grinding wheels of various widths may be used in connection with shields to help reduce the scattering of debris and for safety purposes. Passing the glass substantially consistently under the deletion head efficiently “deletes” the coating from the glass so that it can be used, for example, in connection with the above-described and/or other articles. Wider or narrower grinding wheels may be used to delete more or less coating from the glass surface.
Although edge deletion tables can be used in a variety of applications, they unfortunately have their limitations. For example, edge deletion tables oftentimes are large and require additional machinery in a process line. The addition of process steps can increase delivery time and costs. Edge deletion tables, by their nature, can also create debris that needs to be dealt with accordingly.
Moreover, although edge deletion tables oftentimes are suitable for edge deletion, as their name implies, they oftentimes are limited in the ability to remove coatings in interior areas. This can become increasingly problematic as the area(s) to be removed become smaller and smaller, as there is a practical limit to the size reductions possible for grinding wheels and the like. Conventional edge deletion tables oftentimes are unsuitable for a variety of electronics applications, e.g., where thin lines of demarcation between electrically conductive areas are needed.
Silver pastes are commonly used to form electrical connections with metal conductive layers. See, for example, U.S. Publication No. 2010/0330309 and U.S. Pat. Nos. 4,941,929; 8,664,570; and 8,668,798, which references describe example silver frits/pastes and are hereby incorporated by reference herein in their entireties. The silver paste typically is made to penetrate the top layer (or layers) of oxidized or ceramic films so as to come into contact with a metallic conductive layer(s).
Unfortunately, however, silver pastes are not always able to penetrate the topmost layer (or layers) of all thin film coatings to reach the metallic conductive layer(s), particularly in cases where the layer (or layers) provided over the metallic conductive layer(s) are very strong dielectrics. For instance, when the design of the coating stack includes top layers of transitional elements or compounds including, for example, Zirconium, Scandium, Titanium, Vanadium, Yttrium, Niobium, Lanthanum, Hafnium, and/or Tantalum, highly dielectric films with high surface strengths may be created. Standard silver pastes commercially used in the market today often will not penetrate these highly dielectric films and thus will not create an electrical contact to the metal current-transmitting layers within the coating stack design. Furthermore, in applications where it is desirable to eat all the way through the coating, many conventional silver pastes will be insufficient, as they may not even reach through top dielectric material(s). Improvements have been made in connection with forming electrical connections when thick dielectric materials have been made (see, for example, U.S. Pat. No. 9,085,051, the entire contents of which are hereby incorporated herein by reference), but such improvements are designed to facilitate electrical connections as opposed to completely dissolving a coating. Silver and/or other pastes also may be impractical for large area deletions.
Certain example embodiments address these and/or other concerns. For example, certain example embodiments relate to heating a ceramic paint applied to a portion of a coated article in order to at least partially “eat through” the underlying coating, with any remaining materials being removable by washing, and associated articles. Such techniques may be used in place of, or together with, mechanical edge deletion, patterning, laser scribing, ion beam milling, and/or other techniques.
In certain example embodiments, a method of making a coated article including a sputter-deposited coating supported by a glass substrate is provided. A coating-dissolving material is applied over and contacting the sputter-deposited coating in one or more areas in which the sputter-deposited coating is to be removed. The glass substrate with the coating-dissolving material applied over and contacting the sputter-deposited coating is heated at a temperature of 500-700 degrees C. for no more than 10 minutes. The heating causes the sputter-deposited coating under the coating-dissolving material to be at least partially damaged in the one or more areas in which the sputter-deposited coating is to be removed but does not cause undesired damage to the sputter-deposited coating in other areas. Following the heating, the glass substrate is washed to remove excess material(s) from the glass substrate in the one or more areas in which the sputter-deposited coating is to be removed, in making the coated article. The coating comprises a plurality of dielectric layers.
In certain example embodiments, a method of making a coated article including a sputter-deposited coating supported by a glass substrate is provided. The glass substrate with a coating-dissolving material applied over and contacting the sputter-deposited coating in one or more areas in which the sputter-deposited coating is to be removed is heated, with the heating at least partially dissolving the sputter-deposited coating in the one or more areas in which the sputter-deposited coating is to be removed but elsewhere not dissolving the sputter-deposited coating, and with the heating being performed in connection with heat treatment and/or heat bending of the glass substrate. Following the heating, the glass substrate is washed to remove excess material(s) from the glass substrate in the one or more areas in which the sputter-deposited coating is to be removed, in making the coated article.
In certain example embodiments, an intermediate coated article comprises a glass substrate; a sputter-deposited coating supported by the glass substrate; and a coating-dissolving material applied over and contacting the sputter-deposited coating in one or more areas in which the sputter-deposited coating is to be removed, the coating-dissolving material having a composition selected so as to be heatable at temperatures used in heat treatment and/or heat bending of the glass substrate to cause the sputter-deposited coating to dissolve in the one or more areas in which the sputter-deposited coating is to be removed and to thereafter be removable by washing.
According to certain example embodiments, the coating-dissolving material may be a ceramic paint that, after heating, is removable by washing with water; and the sputter-deposited coating may be a functional (e.g., low-E, AR, conductive, UV-blocking, reflective, solar control, etc.) coating comprising multiple thin film layers.
The features, aspects, advantages, and example embodiments described herein may be combined to realize yet further embodiments.